ジンコウリンナイ ノ カソウニ オケル オオバアサガラ ノ セイチョウ ト リッチカンキョウ

オオバアサガラ(Pterostyrax hispidus SIEB. et Zucc)は,シカの食害地において被害の少ない樹種の一つである。そこで,食害によって林床植生が消失した人工林の土壌流亡などを軽減する方法の一つとして,本種を林床植生に種子散布や植栽で導入する諸条件を検討した。試験地はカラマツ林,サワグルミ林を対象にし,それら試験地の下層木として成育する天然生オオバアサガラを対象に生育状況の異なる5プロットを設定した。その結果,林内相対照度が高いほどオオバアサガラの成立本数,平均樹高,平均根元直径,根元断面積合計のいずれも増大する傾向を示した。さらに,微地形的には凸地より凹地の方で,急斜面よりも緩斜面において生育は良好であった。 これらことからシカの林床植生食害が激しい人工林で本種の天然更新が可能な場所としては,種子供給源である母樹が近くにあり,林内相対照度が 20% 以上で,凹地の緩傾斜地が有力である。また,人工植栽する場合も,凹地形や平坦面に植栽し,林内相対照度に配慮する必要がある。Pterostyrax hispidus, which is not consumed by sika deer, grows in regions that have experienced severe browsing damage. We examined whether introducing P. hispidus to managed forests with poor ground conditions would help preserve the forest floor. Investigation plots were established within a natural community of P. hispidus that grows within managed forests containing Larix kaempferi and Pterocarya rhoifolia . We found that the relative light intensity affected the stand density, height growth, basal diameter, and basal area of P. hispidus and that growth of P. hispidus was better under trees with concave, rather than convex, topography. These results suggest that natural regeneration was succeeding and that P. hispidus seeds will grow in target areas if the relative light intensity is equal to or more than 20% and the canopy topography is concave

カラマツ ヒノキ ニダンリン ニ オケル ヒノキ ノ セイチョウ モデル コウチク ト ケントウ

近年,長伐期林施業とともに複層林施業が重要視されている。しかし,複層林に関する情報が不足している。そのなかでも複層林の収穫予測については,上木・下木の生育条件,施業方法が一様でないことに加えてデータ不足から手探り状態にある。本研究では,カラマツ・ヒノキ二段林の成長予測をするために密度管理図,収量比数,相対照度,成長抑制率を取り入れた成長予測モデルを提案した。そのモデルによっていくつかのタイプのモデル林を想定して上木と樹下植栽木(下木)の成長を予測した。それらの推定された値の信頼度をみるために,東京都水源林で調査したカラマツ・ヒノキ二段林の実測値と比較した。その結果,推定値は実測値と大きな差はなく,提案したモデルは信頼でき,下木の成長過程を求めることに有効であることが示唆された。It is difficult to predict the yield of multiple- layered stands, because there are differences in the growth process between under-storied trees and over-storied trees. The purpose of this study is to clarify the amount of growth in Larix leptolepis-Chamaecyparis obtusa multiple-layered stand by the simulation of growth prediction model. The simulation models were made under the control of four elements ; the yield-density diagram, yield index, relative illumination and the rate of growth. The actual growth was measured in the water conservation forests of Tokyo Metropolis. Approximately , the growth prediction model agreed with result of the actual stands. Therefore, the model was considered to be effective for estimating the growth of under-storied trees with multiple- layered stands

Vagus-macrophage-hepatocyte link promotes post-injury liver regeneration and whole-body survival through hepatic FoxM1 activation

The mechanisms underlying the regenerative capacity of the liver are not fully understood. Here, the authors show that the acute regenerative response to liver injury in mice is regulated by the communication involving the vagus nerve, macrophages, and hepatocytes, leading to hepatic FoxM1 activation and promotion of overall survival

シンヨウジュ ジンコウリン ト コウヨウジュ ニジリン トノ ミミズ グンシュウ ノ ヒカク

スギやヒノキ等の針葉樹の単一樹種からなる人工林では,生物相が単純になることが指摘されている。そこで本研究では,森林施業とミミズ群集の種多様性との関係を明らかにすることを目的とし,静岡県富士宮市麓および東京都西多摩郡奥多摩町のヒノキ人工林,スギ人工林,広葉樹二次林のミミズ群集について調査を行った。両調査地において,広葉樹二次林で最も種数と種多様度が高く,次いでスギ人工林であった。また,両調査地で最も種数が少なかったヒノキ人工林で出現した種は,広葉樹二次林,スギ人工林でも共通にみられる傾向にあった。各林分では,上木の種類,土壌物理化学性などの環境要因が異なることによって,ミミズの種組成や,個体数密度に影響を及ぼすと考えられた。特に,今回の調査結果からはミミズが生息する環境要因の一つに,リターの堆積量と質及び下層植生の種類と量が関わっていることが示唆された。It is well known that artificial monoculture forests, such as Sugi (Crypotomeria japonica) and Hinoki (Chamaecyparis obtusa) forests, have low biodiversity. The objective of this study is to examine the effects of forest management on earthworm diversity, and earthworm communities were compared among living Hinoki, Sugi and broad-leaved secondary forests in two sites, Fujinomiya city, Shizuoka Prefecture and Okutama, Tokyo Prefecture. In both sites, broad-leaved secondary forests had the highest diversity among the three forest types, and Hinoki forests showed the lowest. Species which occurred in Hinoki forests commonly appeared in the other forests. It was concluded that the species composition and individual density of earthworm communities were influenced by vegetation and soil physicochemical qualities. Especially, the amount and quality of litter and species diversity and biomass of understory plants are important factors for the habitat evaluation of earthworms

オクタマ ニ オケル シンヨウジュジンコウリン ト コウヨウジュニジリンナイ デノ ノネズミルイコタイグンドウタイ

森林施業に関わる野ネズミ類の役割を明らかにする一環として,林相の異なる針葉樹人工林と広葉樹二次林を跨ぐ形で林内に生息する野ネズミ類を捕獲・放獣する方法により2006年から2009年まで個体群の変動を調査した。その結果,調査対象としたアカネズミ(Apodemus speciosus),ヒメネズミ(Apodemus argenteus)の捕獲個体数は2006年9月には延べワナ数675個で157個体,422回と最高の高密度状態を記録したが,11月から急激な減少が認められ,その後は1年以上ひと月の捕獲個体が数頭という低密度で推移したことから,野ネズミ類個体群にクラッシュが生じたものと判断した。アカネズミとヒメネズミの捕獲個体数の変動を比較すると,それぞれの生息特性を反映して急減の時期に3か月の時間的差異が見られた。しかし,全体的な変動の傾向は両種とも同様の推移を示した。針葉樹林と広葉樹林での生息状況を見ると,アカネズミでは広葉樹林の利用頻度が高く,秋季から冬季にかけて針葉樹林の依存度が増す傾向にあった。ヒメネズミでは針葉樹林のみの利用個体が多いものの,年によっては夏季に広葉樹林のみ利用する個体が増加した。また,いずれの種とも両方の林分を同時に利用している個体は少ないという傾向を得た。行動範囲に関しては,高密度下では大きく,ランダムに分布し,低密度下では小さく,限定的になる傾向が見られた。As a part of clarifying up the role of the forest field mouse, we investigated the fluctuation of the mouse population at an area between a coniferous plantation and a broad-leaved secondary forest in Okutama area, Tokyo. We attempted the capture-recapture method from 2006 to 2009. In September 2006, the captured number of the Apodemus speciosus and A. argenteus surveyed recorded the maximum (157 individuals, 422 caputures in 675 trap night ), but it started decreasing suddenly from November. We judged that a sudden drop occurred in the field mouse population because the captured number of these mice remained low over the next year. Start of the drop in A. argenteus was delayed three months compared to that of A. speciosus. However, both species had a similar population fluctuation tendency. A. speciosus generally used the broad-leaved forest frequently, and they showed increased dependence on the coniferous forest in fall. A. argenteus generally preferred the coniferous forest, but in summer some individuals of both species used only the broad-leaved forest. There were not many individuals whose home ranges extended across both kinds of forests. Home ranges of the field mice tended to be wide and random under a high density situation, but they became narrow and clustered under a low density situation

オオバアサガラ PTEROSTYRAX HISPIDA ノ サシキ ニ オヨボス サシホ ノ ナガサ ト ハッコンソクシンホウ ニ カンスル ケンキュウ

オオバアサガラ(Pterostyrax hispida)は,シカ食害地における林床植生の回復にあたって,高木になりシカが低嗜好性を示す樹種である。オオバアサガラの導入を図るために,挿し木による増殖法を調べた。挿し木試験は,本種の2年生萌芽枝による挿し穂を,鹿沼土を床土としたプランターに挿し付けることによって行った。発根促進処理の効果,および挿し穂長の違いと発根等の関係を調べた。発根促進処理には粉剤,液剤のオキシベロン (IBA) を用い,挿し穂長を15cmと30cmに変えて試験した。試験の結果,挿し付けから2,3週間でカルスが形成され,3,4週間で発根が始まった。挿し穂長の違いでは30cmの挿し穂で良好な発根が認められた。特に発根促進処理を施すことで旺盛なカルス形成,発根が確認された。したがって,発根促進剤を処理することで,より活力のある挿し木苗の生産が可能といえる。処理剤の選択にあっては,取り扱いのしやすさおよび発根の早さから粉剤の方が適しているといえる。Serious forest floor vegetation damage by deer grazing has been extensive in the Okutama region in Tokyo. Such damage has also caused forest soil erosion. One of the solutions for the problem, planting the particular tree species for which deer have less appetite, can be effective. Pterostyrax hispida is one of the species which have regenerated and grown vigorously in Okutama region, so we believe it is one of the suitable species for planting. We attempted rooted cutting method of Prostyrax hispida. On the cutting examination, two years-old sprouts from rootstock of natural young trees were used for scions of cutting, and then were embedded into Kanuma soil of planters. In addition, we tested IBA (Oxyberon) treatment and scion length. After cutting, most of scions formed callus and root from 2 to 3 weeks and 3 to 4 weeks, respectively. The results showed that IBA accelerated rooting and making callus. 30cm length scions made more roots than 15cm ones. Therefore, we recommend the use of the scion of 30cm for propagation. We also compared between powder and liquid IBA, but there were few differences between the treatment methods. However, we would recommend the powder type because of easier and more efficient treatments. From these results, we reached the conclusion that rooted cutting is a safe and efficient method for the propagation of Prostyrax hispida

Misfolded proinsulin in the endoplasmic reticulum during development of beta cell failure in diabetes

The endoplasmic reticulum (ER) is broadly distributed throughout the cytoplasm of pancreatic beta cells, and this is where all proinsulin is initially made. Healthy beta cells can synthesize 6000 proinsulin molecules per second. Ordinarily, nascent proinsulin entering the ER rapidly folds via the formation of three evolutionarily conserved disulfide bonds (B7–A7, B19–A20, and A6–A11). A modest amount of proinsulin misfolding, including both intramolecular disulfide mispairing and intermolecular disulfide‐linked protein complexes, is a natural by‐product of proinsulin biosynthesis, as is the case for many proteins. The steady‐state level of misfolded proinsulin—a potential ER stressor—is linked to (1) production rate, (2) ER environment, (3) presence or absence of naturally occurring (mutational) defects in proinsulin, and (4) clearance of misfolded proinsulin molecules. Accumulation of misfolded proinsulin beyond a certain threshold begins to interfere with the normal intracellular transport of bystander proinsulin, leading to diminished insulin production and hyperglycemia, as well as exacerbating ER stress. This is most obvious in mutant INS gene–induced Diabetes of Youth (MIDY; an autosomal dominant disease) but also likely to occur in type 2 diabetes owing to dysregulation in proinsulin synthesis, ER folding environment, or clearance.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143748/1/nyas13531.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143748/2/nyas13531_am.pd

Biosynthesis, structure, and folding of the insulin precursor protein

Insulin synthesis in pancreatic β-cells is initiated as preproinsulin. Prevailing glucose concentrations, which oscillate pre- and postprandially, exert major dynamic variation in preproinsulin biosynthesis. Accompanying upregulated translation of the insulin precursor includes elements of the endoplasmic reticulum (ER) translocation apparatus linked to successful orientation of the signal peptide, translocation and signal peptide cleavage of preproinsulin-all of which are necessary to initiate the pathway of proper proinsulin folding. Evolutionary pressures on the primary structure of proinsulin itself have preserved the efficiency of folding ("foldability"), and remarkably, these evolutionary pressures are distinct from those protecting the ultimate biological activity of insulin. Proinsulin foldability is manifest in the ER, in which the local environment is designed to assist in the overall load of proinsulin folding and to favour its disulphide bond formation (while limiting misfolding), all of which is closely tuned to ER stress response pathways that have complex (beneficial, as well as potentially damaging) effects on pancreatic β-cells. Proinsulin misfolding may occur as a consequence of exuberant proinsulin biosynthetic load in the ER, proinsulin coding sequence mutations, or genetic predispositions that lead to an altered ER folding environment. Proinsulin misfolding is a phenotype that is very much linked to deficient insulin production and diabetes, as is seen in a variety of contexts: rodent models bearing proinsulin-misfolding mutants, human patients with Mutant INS-gene-induced Diabetes of Youth (MIDY), animal models and human patients bearing mutations in critical ER resident proteins, and, quite possibly, in more common variety type 2 diabetes

MicroRNA Dysregulation in the Spinal Cord following Traumatic Injury

Spinal cord injury (SCI) triggers a multitude of pathophysiological events that are tightly regulated by the expression levels of specific genes. Recent studies suggest that changes in gene expression following neural injury can result from the dysregulation of microRNAs, short non-coding RNA molecules that repress the translation of target mRNA. To understand the mechanisms underlying gene alterations following SCI, we analyzed the microRNA expression patterns at different time points following rat spinal cord injury